Firewalls – Reliable Line of Defence Against Cyberattacks

What Are Firewalls and How Do They Work?

A firewall is a network security device or software that enforces a set of rules to determine whether to allow or block traffic. Acting like a security guard, it prevents unauthorised access to your network while permitting legitimate communication. Firewalls can be hardware-based, software-based, or cloud-based.

Types of Firewalls

• Packet-Filtering Firewalls: Analyse data packets based on predefined rules.
• Stateful Inspection Firewalls: Track active sessions to provide dynamic security.
• Next-Generation Firewalls (NGFWs): Combine traditional firewall functions with advanced features like intrusion prevention and application awareness. A good example is FortiGate from Fortinet.

Best Practices for Firewall Management

• Enable Logging and Monitoring: Review logs regularly to detect unauthorised access attempts.
• Keep Firewalls Updated: Regular updates ensure protection against emerging threats.
• Establish Strict Rulesets: Implement a least-privilege model by blocking unnecessary ports and services.
• Segment Your Network: Use firewalls to create internal boundaries, preventing attackers from accessing sensitive data if they breach one segment.
• Deploy Firewalls at All Endpoints: Protect not only the perimeter but also remote devices and cloud services.

Signs Your Firewall Needs Attention

• Frequent false positives or negatives.
• Unpatched vulnerabilities due to outdated firmware or software.
• Overly permissive rules that allow unnecessary traffic.